Overhead trolley conveyor systems are used in a variety of settings in manufacturing and fabricating plants (automotive assembly lines, paint finishing lines, etc.), as well as in food processing plants. A typical conveyor system includes a track, a number of trolley assemblies riding on the track, and a drive mechanism that moves the trolleys along the track. A basic trolley assembly includes one or more trolley wheel assemblies that ride on the track and some form of bracket capable of suspending an item from the track. Different trolley wheel assemblies are used depending upon the particular setting and performance requirements, but in general a trolley wheel assembly includes a wheel with some form of bearing assembly.
During use, the trolley assemblies are subjected to a variety of environments in which the wheel assemblies can get dirty over a period of time. Trolley performance can degrade as the bearing assemblies become dirty. In many cases, debris and other contaminants within a bearing assembly can reduce the operational quality or life of the bearing assembly. Some trolley assemblies have closed, sealed, or shielded bearing assemblies that seek to prevent debris from entering the bearing assembly and degrading the bearing operation. Such bearing assemblies, however, can be difficult to maintain, difficult to relubricate, and/or they may not operate as effectively as open bearings. Moreover, when debris does enter such a bearing assembly, the debris can be extremely difficult to remove. When open bearing assemblies are used, periodic cleaning (e.g., through manual or automatic washing, such as spraying with water containing a cleaning or sterilizing agent) may be required.